Arrangement for supporting a symbol in an illuminated instrument

ABSTRACT

An arrangement including an optical wedge for transmitting light from a light source to illuminate an instrument and a display symbol which is supported by a light pipe mounted to the optical wedge to eliminate supporting members which detract from the display.

United States Patent Marko Dec. 10, 1974 ARRANGEMENT FOR SUPPORTING A 2,761,056 8/1956 L820 240/21 SYMBOL IN AN ILLUMINATED g; lsiturlblm 240 I earns INSTRUMENT 3,263,646 8/1966 Arnold et al 116/129 R [75] Inventor: Albert J. Marko, Colts Neck, NJ. 3,561,145 2/ 1971 Shotwell 240/1 EL [73] Assignee: The Bendix Corporation, Teterboro,

NJ. Primary Examiner-Louis J. Capozi F. Filed: J 1972 fitatptrzney, Agent, or Fzrm Anthony Cuoco S H [21] Appl. No.: 262,841

52 us. 01. 116/129 R, 240/21 [57] ABSTRACT [51] hit. Cl. G09f 9/00 An arrangement including an optical wedge for trans [58] held of Search 116/129 114; mitting light from a light source to illuminate an in- 33/327, 328, 329, 330, 40/130 R, 240/1 EL, strument and a display symbol which is supported by a light pipe mounted to the optical wedge to eliminate supporting members which detract from the display. [56] References Cited UNITED STATES PATENTS 5 Claims, 2 Drawing Figures 2,404,603 7/1946 Summers, Jr. 33/329 J! l 2 y g 1 7 ARRANGEMENT FOR SUPPORTING A SYMBOL IN AN ILLUMINATED INSTRUMENT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to illuminated instruments having display symbols and, more particularly, to means for supporting the symbols without detracting from the display.

2. Description of the Prior Art Aircraft attitude indicating instruments have symbols which are read against an illuminated member that moves in accordance with the attitude of the craft. Prior to the present invention, means for supporting the symbols detracted from the display characteristics of the instrument.

SUMMARY OF THE INVENTION The arrangement of the invention makes use of a light pipe mounted to a lighting wedge which transmits light to illuminate an instrument. The light pipe supports a symbol and transmits nearby light from the wedge for providing, in effect, invisible means for supporting the symbol, so as not to detract from the display characteristics of the instrument.

One object of this invention is to support a symbol in an illuminated instrument without detracting from the display characteristics of the instrument.

Another object of this invention is to make effective use of a light pipe mounted to a lighting wedge for supporting the symbol. The light pipe transmits light transmitted by the wedge and thus does not detract from the display characteristics of the instrument.

Another object of this invention is to eliminate symbol supporting means which detract from the display characteristics of the instrument.

The foregoing and other objects and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description which follows, taken together with the accompany drawings wherein one embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for illustration purposes only and are not to be construed as defining the limits of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric pictorial representation of an aircraft attitude indicating instrument of the type described.

FIG. 2 is a sectional view taken along the lines 2-2 in FIG. 1 and showing symbol supporting means to the invention.

DESCRIPTION OF THE INVENTION FIG. 1 shows an elongated can or casing l in which an aircraft attitude indicating instrument is contained. Can 1 is closed at its open or viewing end by a vertically disposed bezel window 2. Rearwardly of the window is fixed a dial plate 3 having a circular open central area about which borders a radially narrow dial face 4 divided into degrees as shown in FIG. 1. Extending horizontally across the open area of plate 3 is an aircraft symbol 5. Symbol 5 is supported as will be hereinafter described with reference to FIG. 2. Casing l is intended to be fixed in the aircraft instrument panel in a level position so that the dial faces the pilot. A bezel 7 in front of bezel window 2 accommodates bolts for securing the instrument in the instrument panel of the craft.

In close proximity to the rear of the bezel window 2 and the dial face 3 is a truncated spherical shell 8 of very light weight material such as aluminum. The upper half of the face portion of this sphere may be suitably colored blue so as to indicate sky. The lower half of the sphere may be colored brown or black to indicate earth. The division point of the colored sections pro vides a horizon line 9 which has a normal position when the instrument is level coinciding with aircraft symbol 5.

Sphere 8 functions to roll or rotate on a horizontal axis as the aircraft pitches so as to indicate climbing and diving attitudes of the craft. Lateral markings (not shown) in contrasting colors on the respective colored areas of the sphere serve to indicate the degree of pitch relative to the aircraft symbol as the sphere rolls on its horizontal axis. Rotation of sphere 8 is gyro controlled. An instrument of this type is described and claimed in US. Pat. No. 2,912,766 issued Nov. 17, I959 to Charles E. Hurlburt and assigned to The Bendix Corporation, assignee of the present invention.

With reference now to FIG. 2, a lighting wedge 10 is disposed behind bezel window 2 and is supported within bezel 7. The large end of the wedge is at the top and the small end is at the bottom of the bezel. Wedge 10 may be of a suitable optical glass or of an optical plastic such as Thermo Polacrylate.

A lighting assembly 16 is disposed at the top of bezel 7 near the large end of wedge 10. Lighting Assembly 16 may include a base 18 and light bulbs 20.

A light pipe 30, which may be of the same material as lighting wedge 10, has a base portion 32 and a stem portion 34. Base portion 32 is mounted to rear surface 10A of lighting wedge 10 by cementing with, for example, a clear translucent cement. Aircraft symbol 5 is suitably secured to stem portion 34 of light pipe 30.

In operation light from bulbs 20 is transmitted through wedge 10 to illuminate the instrument including sphere 8. Light is directed through the lighting wedge toward the instrument. Light from lighting wedge 10 near light pipe 30 is transmitted by the light pipe so that when an observer looks through the front of the instrument only aircraft symbol 5 is visible as best shown in FIG. 1.

The advantages and novel features of the invention are best understood when it is considered that prior thereto supporting members were necessary to adequately support aircraft symbol 5 for viewing by an observer. Thus. in one form of the prior art supporting anns were suitably secured to surface 10A of lighting wedge 10 and aircraft symbol 5 was mounted to the supporting arms. In another fomi of prior art a glass plate member was mounted to the instrument in back of lighting wedge 10 and the aircraft symbol was suitably cemented or otherwise bonded to the glass plate. In either event, the display characteristics of the instrument were degraded and additional and more costly assembly resulted.

The present invention eliminates the aforenoted disadvantages of prior art arrangements. The use of the light pipe for supporting the aircraft symbol provides in efiect invisible support means and facilitates assembly of the instrument.

Although but a single embodiment of the invention has been illustrated and described in detail, it is to be expressly understood that the invention is not limited thereto. Various changes may also be made in the design and arrangement of the parts without departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art.

, What is claimed is:

1; For use with an instrument of the type having:

' an elongated case with a viewing end;

a bezel mounted to the viewing end of the case;

a vertically disposed viewing window supported within the bezel for closing the viewing end; and indicating means supported within the case for displacement about an axis in response to a condition;

posed light transmitting member and supporting a marker between said face and the indicator means and transmitting nearby light transmitted by the vertically disposed member so as to be invisible when viewing the indicator and symbol through the viewing window.

2. An instrument as described by claim 1, wherein:

the vertically disposed light transmitting member is an optical wedge having its large end near the top of the instrument and adjacent the light source and its small end near the bottom of the instrument.

3. An instrument as described by claim 2, wherein:

the horizontally disposed light transmitting member is a light pipe having a base portion and a stem portion;

the base portion is supported on the rear face of the wedge so that the second member is in a plane normal to that of the first member; and

the stern portion supports the marker.

4. An instrument as described by claim 2, wherein:

the horizontally disposed light transmitting member is disposed intermediate the large and small ends of the wedge.

5. An instrument as described by claim 2, wherein:

the base portion of the light pipe is conical and the stem portion is cylindrical. 

1. For use with an instrument of the type having: an elongated case with a viewing end; a bezel mounted to the viewing end of the case; a vertically disposed viewing window supported within the bezel for closing the viewing end; and indicating means supported within the case for displacement aboUt an axis in response to a condition; illuminating means comprising: a light source supported within the bezel and at the top thereof; a vertically disposed light transmitting member supported within the bezel in back of the viewing window and adjacent the light source, and having a front face adjacent said window and a rear face adjacent the indicator, said member transmitting light from the light source to the indicator means to illuminate said indicator means; and a horizontally disposed light transmitting member supported on the rear face of the vertically disposed light transmitting member and supporting a marker between said face and the indicator means and transmitting nearby light transmitted by the vertically disposed member so as to be invisible when viewing the indicator and symbol through the viewing window.
 2. An instrument as described by claim 1, wherein: the vertically disposed light transmitting member is an optical wedge having its large end near the top of the instrument and adjacent the light source and its small end near the bottom of the instrument.
 3. An instrument as described by claim 2, wherein: the horizontally disposed light transmitting member is a light pipe having a base portion and a stem portion; the base portion is supported on the rear face of the wedge so that the second member is in a plane normal to that of the first member; and the stem portion supports the marker.
 4. An instrument as described by claim 2, wherein: the horizontally disposed light transmitting member is disposed intermediate the large and small ends of the wedge.
 5. An instrument as described by claim 2, wherein: the base portion of the light pipe is conical and the stem portion is cylindrical. 